My /usr partitions don't have a huge amount of space, in some cases only 400MB. Is there any way I can install Softaculous in a partition other than /usr? Or can I force it to place some of its data in other partitions?
Sir which panel are you using ?
If it is a custom panel then you can install it anywhere.
Also Softaculous uses just 13MB approx in the /usr partition and the scripts are located at /var/softaculous folder so the load on /usr is very less.